New AMRC machine could boost hopes for tailor-made implants

28 July 2014

Medical implants, tailor made for individual patients, could be closer to reality, following the installation of a state of the art grinding machine at the University of Sheffield Advanced Manufacturing Research Centre (AMRC) with Boeing.

The new, PROFIMAT MC607, 5-axis CNC grinding machine, made by German company Blohm Jung, is one of the most flexible machines of its type and has been installed at the AMRC Design Prototyping and Testing Centre.

One of the moving column grinding machine's key roles will be to enable researchers to increase understanding of how materials behave during grinding.

Future plans include using the grinder to create a high quality finish on artificial knee joints, made from cobalt-chrome powder, using 3D printing technology.

3D printing could bring major benefits for patients and is one area of research being investigated by the newly established Medical AMRC, which is on the same site as the AMRC.

At present, patients needing replacement knees have to make do with the best possible match from a range of standard sizes.

In future, the joint being replaced could be scanned so that a 3D replica can be made that would be a perfect match.

"The big advantage is the joint is bespoke, so you are replacing like for like and 3D printing saves on material, so there is the potential to reduce weight," says Dr Andy Bell, from the AMRC Design & Prototyping Group.

"However, the surface isn't of a high enough quality for components used in a replacement joint, so it has to be very, very highly finished, which is where the grinder comes in."

Its 24-position tool magazine can hold mills, drills and other cutters, as well as grinding wheels up to 400 mm in diameter and 100 mm wide.

That allows the number of separate machining operations to be reduced, often to just one, cutting manufacturing costs and, when combined with the eight tonne machine's increased rigidity, increasing accuracy.

The machine also boasts significantly higher positioning speeds and a wheel cleaning system that helps to keep grinding wheels sharp, while maintaining their profile, allowing increased feed rates.